how do I get past this level. The large barrel keeps spitting out smaller barrels who keep rolling toward me. I've tried jumping on them and tried jumping in the big barrels mouth but nothing works I'm stuck here. I am new to this game as you can tell.

Jump on a barrel to break it open. Then, jump on the beetle that pops out and pick it up. The idea is to keep throwing beetles into the boss' mouth until it belches itself off the edge of the platform.

In the future, take a look at the FAQs/Guides section (there's a link to it right above where the top post is). There was a walk-through on the list that focused on the game's bosses.